Its better than new like this... Its proven.
I always tested parts, mostly to just make sure it works as it should, and if not to find out before any warranty expires.
Many buy parts like this ahead of time while planning and piecing together a project and let the bits sit for a long time.

I always test everything I get. It is good habit. I bought a speed controller I long time ago (not this air boss) and found out it didn't work. I didn't plan on selling this esc but now I have an extra esc bc I crashed a plane recently...hence I'm selling wings from a 3dhs plane